Common small portable hoists are of two main types,
the chain hoist or chain block and the wire rope or cable type.
Chain hoists may have a lever to actuate the hoist or have a loop of
operating chain that one pulls through the block (known
traditionally as a chain fall) which then activates the block to
take up the main lifting chain.
A hand powered hoist with a ratchet wheel is known as a "ratchet
lever hoist" or, colloquially, a "Come-A-Long". The original hoist
of this type was developed by Abraham Maasdam of Deep Creek,
Colorado about 1919, and later commercialized by his son, Felber
Maasdam, about 1946. It has been copied by many manufacturers in
recent decades.
Ratchet lever hoists have the advantage that they can usually be
operated in any orientation, for pulling, lifting or binding. Chain
block type hoists are usually suitable only for vertical lifting.
For a given rated load wire rope is lighter in weight per unit
length but overall length is limited by the drum diameter that the
cable must be wound onto. The lift chain of a chain hoist is far
larger than the liftwheel over which chain may function. Therefore,
a high-performance chain hoist may be of significantly smaller
physical size than a wire rope hoist rated at the same working load.
Both systems fail over time through fatigue fractures if operated
repeatedly at loads more than a small percentage of their tensile
breaking strength. Hoists are often designed with internal clutches
to limit operating loads below this threshold. Within such limits
wire rope rusts from the inside outward while chain links are
markedly reduced in cross section through wear on the inner
surfaces. Regular lubrication of both tensile systems is recommended
to reduce frequency of replacement. High speed lifting, greater than
about 60 feet per minute (20 m/min), requires wire rope wound on a
drum, because chain over a pocket wheel generates fatigue-inducing
resonance for long lifts.